Barbaloin pretreatment attenuates myocardial ischemia-reperfusion injury via activation of AMPK

Advances in research on the protective mechanisms of traditional Chinese medicine (TCM) in myocardial ischaemia-reperfusion injury

CONTEXT

Developing effective drugs to treat myocardial ischaemia-reperfusion (MI/R) injury is imperative. Traditional Chinese medicines (TCMs) have had considerable success in the treatment of cardiovascular diseases. Elucidating the mechanisms by which TCMs improve MI/R injury can supplement the literature on MI/R prevention and treatment.

OBJECTIVE

To summarise TCMs and their main protective mechanisms against MI/R injury reported over the past 40 years.

METHODS

Relevant literature published between 1980 and 2020 in Chinese and English was retrieved from the Web of Science, PubMed, SpringerLink, PubMed Central, Scopus, and Chinese National Knowledge Infrastructure (CNKI) databases. Search terms included 'medicinal plants', 'myocardial ischaemia reperfusion injury', 'Chinese medicine prescriptions', 'mechanisms', 'prevention', 'treatment' and 'protection'. For inclusion in the analysis, medicinal plants had to be searchable in the China Medical Information Platform and Plant Database.

RESULTS

We found 71 medicinal species (from 40 families) that have been used to prevent MI/R injury, of which Compositae species (8 species) and Leguminosae species (7 species) made up the majority. Most of the effects associated with these plants are described as antioxidant and anti-inflammatory. Furthermore, we summarised 18 kinds of Chinese compound prescriptions, including the compound Danshen tablet and Baoxin pill, which mainly reduce oxidative stress and regulate mitochondrial energy metabolism.

DISCUSSION AND CONCLUSIONS

We summarised TCMs that protect against MI/R injury and their pharmacological mechanisms. This in-depth explanation of the roles of TCMs in MI/R injury protection provides a theoretical basis for the research and development of TCM-based treatment drugs.

Effect of Traditional Chinese Medicine on the Cardiovascular Diseases

Background: Traditional Chinese medicine (TCM) is the health care system developed with the help of clinical trials that are based ideally on the scientific model of regulation. Objective: This systematic health care system relies on some specific unique theories and practical experiences to treat and cure diseases, thus enhancing the public's health. Review Methodology: The current review covers the available literature from 2000 to 2021. The data was collected from journals research articles, published books, thesis, and electronic databases, search engines such as Google Scholar, Elsevier, EBSCO, PMC, PubMed, ScienceDirect, Willey Online Library, Springer Link, and CNKI) searching key terms, cardiovascular disease, traditional Chinese medicines, natural products, and bioactive compounds. Full-length articles and abstracts were screened for the collection of information included in the paper. Results: Clinical trials on the TCM and basic research carried out on its mechanism and nature have led to the application and development of the perfect design of the research techniques, for example, twofold striking in acupuncture that aid in overcoming the limitations and resistances in integrating and applicability of these experiences and trials into the pre-existing biomedical models. Furthermore, TCM has also been utilized from ancient times to treat heart diseases in Asia, particularly in China, and is now used by people in many other areas. Cardiovascular disease (CVD) is mainly developed by oxidative stress. Hence antioxidants can be beneficial in treating this particular disease. TCM has a wide variety of antioxidant components. Conclusion: The current review article summarizes the underlying therapeutic property of TCM and its mechanism. It also overviews the evidence of the mechanism of TCM action in CVD prevention by controlling oxidative stress and its signaling pathway.

The potential health benefits of aloin from genus Aloe

The Aloe species is known for its medicinal and cosmetic properties. Aloin is an active ingredient found in the leaves of medicinal plants of the genus Aloe. Aloin has attracted considerable interest for its antiinflammatory, anticancer, antibacterial, and antioxidant activities. However, since its clinical application is restricted by its unclear mechanism of action, a deeper understanding of its pharmacological activity is required. This review provides an overview of current pharmacological and toxicological studies published in English from February 2000 to August 2021. Herein, we summarized the sources and potential health benefits of aloin from a clinical application perspective to guide for further studies on the sources of aloin, aimed at efficiently increasing aloin production. Importantly, the function and mechanism of action of aloin remain unclarified. In future research, it is necessary to develop new approaches for studying the pharmacological molecular mechanisms underlying the activity of this compound against various diseases.

The protective effect of allicin on myocardial ischemia-reperfusion by inhibition of Ca2+ overload-induced cardiomyocyte apoptosis via the PI3K/GRK2/PLC-γ/IP3R signaling pathway

Purpose: To investigate the protective effect and mechanism of allicin on myocardial ischemia-reperfusion (MI/R) injury.

Methods: We investigated the mechanisms by which allicin attenuated the MI/R injury by focusing on phosphoinositide 3-kinase, G protein coupled receptor kinases 2, phospholipase Cγ and cardiomyocyte apoptosis. Sixty male mice were randomly assigned into three groups: repeated MI/R (model), sham-operated (control), and MI/R+ allicin group (allicin). Ultrasound examination was used to examine the cardiac function. Masson staining was used to evaluate the myocardial infarct area. TUNEL assay was performed to examine the anti-apoptotic effect of allicin. Differentially expressed genes (DEGs) and pathways were analyzed by mRNA microarray analysis. Immunofluorescence staining and western blot were carried out to detect the effect of allicin on the PI3K. A pan-PLC activator, m-3M3FBS, was applied to investigate whether allicin induced cardiomyocyte apoptosis was via the GRK2/PLC/IP3R signaling pathway.

Results: Masson staining and the TUNEL assay revealed that allicin reduced infarct size and played an anti-apoptotic role in M/IR. Ultrasound examination revealed that allicin improved cardiac function after M/IR injury. Gene ontology analysis indicated that the calcium signaling pathway and PI3KCA(PI3K) were selected. Immunofluorescence staining and western blot exposed that PI3K was activated by allicin during MI/R injury. Fura-2AM staining revealed that the PI3K -mediated GRK2/PLC-γ/IP3R pathway may be involved in the protective effect of allicin on MI/R injury.

Conclusions: Allicin has a protective effect on MI/R injury. This effect might be associated with the inhibition of Ca²⁺ overload-induced apoptosis and the inhibition of the PI3K -mediated GRK2/PLC-γ/IP3R signaling pathway.

CTRP13 Protects H9c2 Cells Against Hypoxia/Reoxygenation (H/R)-Induced Injury Via Regulating the AMPK/Nrf2/ARE Signaling Pathway

Myocardial infarction (MI) is identified as the myocardial necrosis due to myocardial ischemia/reperfusion (I/R) injury and remains a leading cause of mortality. C1q/TNF-related protein 13 (CTRP13) is a member of CTRP family that has been found to be involved in coronary artery disease (CAD). However, the role of CTRP13 in MI remains unclear. We aimed to explore the functional role of CTRP13 in H9c2 cells exposed to hypoxia/reoxygenation (H/R). Our results demonstrated that H/R stimulation significantly decreased the expression of CTRP13 in H9c2 cells. H/R-induced an increase in ROS production and reductions in activities of SOD and CAT were prevented by CTRP13 overexpression but were aggravated by CTRP13 silencing. Moreover, CTRP13 overexpression could reverse the inductive effect of H/R on caspase-3 activity and bax expression, as well as the inhibitory effect of H/R on bcl-2 expression in H9c2 cells. However, CTRP13 silencing presented opposite effects with CTRP13 overexpression. Furthermore, CTRP13 overexpression enhanced the H/R-stimulated the expression levels of p-AMPK and nuclear Nrf2, and Nrf2 transcriptional activity. However, inhibition of AMPK reversed the CTRP13-mediated activation of Nrf2/ARE signaling and the cardiac-protective effect in H/R-exposed H9c2 cells. Additionally, silencing of Nrf2 reversed the protective effects of CTRP13 against H/R-stimulated oxidative stress and apoptosis in H9c2 cells. Finally, recombinant CTRP13 protein attenuated myocardial I/R-induced injury in rats. Taken together, these findings indicated that CTRP13 protected H9c2 cells from H/R-stimulated oxidative stress and apoptosis via regulating the AMPK/Nrf2/ARE signaling pathway. Our results provided evidence for the therapeutic potential of CTRP13 in myocardial I/R injury.

LncRNA Chaer Prevents Cardiomyocyte Apoptosis From Acute Myocardial Infarction Through AMPK Activation

Long non-coding RNA (lncRNA) is widely reported to be involved in cardiac (patho)physiology. Acute myocardial infarction, in which cardiomyocyte apoptosis plays an important role, is a life-threatening disease. Here, we report the lncRNA Chaer that is anti-apoptotic in cardiomyocytes during Acute myocardial infarction. Importantly, lncRNA Chaer is significantly downregulated in both oxygen-glucose deprivation (oxygen-glucose deprivation)-treated cardiomyocytes in vitro and AMI heart. In vitro, overexpression of lncRNA Chaer with adeno virus reduces cardiomyocyte apoptosis induced by OGD-treated while silencing of lncRNA Chaer increases cardiomyocyte apoptosis instead. In vivo, forced expression of lncRNA Chaer with AAV9 attenuates cardiac apoptosis, reduces infarction area and improves mice heart function in AMI. Interestingly, overexpression of lncRNA Chaer promotes the phosphorylation of AMPK, and AMPK inhibitor Compound C reverses the overexpression of lncRNA Chaer effect of reducing cardiomyocyte apoptosis under OGD-treatment. In summary, we identify the novel ability of lncRNA Chaer in regulating cardiomyocyte apoptosis by promoting phosphorylation of AMPK in AMI.

CTRP3 protects hippocampal neurons from oxygen-glucose deprivation-induced injury through the AMPK/Nrf2/ARE pathway

OBJECTIVE

C1q/TNF-related protein 3 (CTRP3), a member of CTRP family, has been found to have neuroprotective effect. In the current study, we investigated the protective role of CTRP3 in hippocampal neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R).

MATERIALS AND METHODS

The mRNA and protein levels of CTRP3 in OGD/R-stimulated hippocampal neurons were measured using qRT-PCR and western blot analysis, respectively. CCK-8 assay was performed to assess cell viability. ROS production was measured using the fluorescence probe 2',7'-dichlorofluorescein diacetate (H₂DCFDA). The activities of SOD and GPx were determined using ELISA. Cell apoptosis was assessed. Luciferase reporter assay was carried out to assess the activation of ARE). The levels of p-AMPK and Nrf2 were measured using western blot.

RESULTS

Our results showed that the expression of CTRP3 was significantly downregulated in hippocampal neuronal cells exposed to OGD/R. Overexpression of CTRP3 improved cell viability of OGD/R-induced hippocampal neurons. In addition, overexpression of CTRP3 attenuated the OGD/R-caused oxidative stress with decreased ROS production and increased activities of SOD and GPx. Moreover, CTRP3 caused a significant increase in bcl-2 expression and decreases in bax expression and caspase-3 activity. Furthermore, CTRP3 overexpression significantly upregulated the levels of p-AMPK and Nrf2, as well induced the activation of ARE in OGD-R-induced hippocampal neurons. CTRP3 upregulated the mRNA expression levels of HO-1, NQO-1 and GPx-3. Additionally, treatment with the inhibitor of AMPK partially reversed the neuroprotective effect of CTRP3 in OGD/R-exposed neurons.

CONCLUSION

CTRP3 exerted protective effect on OGD/R-induced cerebral injury, which was regulated by AMPK/Nrf2/ARE pathway.

Barbaloin Treatment Contributes to the Rebalance of Glucose and Lipid Homeostasis of Gestational Diabetes Mellitus Mice

Aloe vera L has been shown to possess hypoglycemic and hypolipidemic effects on type 2 diabetic patients, and its major benefits may be linked to barbaloin, which is a major component of Aloe vera L. This study focused on investigating the potential effects and underlying mechanisms of barbaloin on gestational diabetes mellitus (GDM). The db/+ diabetic mice with GDM were daily orally administered with barbaloin or metformin during the gestational period. The results demonstrated that administration of barbaloin significantly reduced blood glucose levels and increased insulin levels in GDM mice. We further found that barbaloin treatment reduced inflammatory response and ROS levels in the liver. Finally, we revealed that the AMP-activated protein kinase (AMPK) / peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) signaling pathway was involved in BAT-mediated beneficial effects on mice with GDM. Our study suggested that barbaloin exerted hypoglycemic and hypolipidemic effects on GDM mice, via, at least in part, modulation of AMPK/ PGC-1α signaling in GDM mice.

Aloin protects mice from diet-induced non-alcoholic steatohepatitis via activation of Nrf2/HO-1 signaling

Aloin, a naturally occurring anthraquinone glycoside derived from the Aloe species, has antioxidant and anti-inflammatory activities, but its role in non-alcoholic steatohepatitis (NASH) remains unknown. This study was designed to investigate the anti-inflammatory, antioxidant, and anti-apoptotic effects of aloin and the underlying mechanisms during NASH. Wild-type or nuclear erythroid 2-related factor 2 (Nrf2) knock-out (KO) mice were fed a choline-deficient, l-amino acid-defined, high-fat (CDAAH) diet and treated with aloin (10, 20 or 40 mg per kg bw per day) by gavage for twelve weeks. Liver and blood samples were collected to evaluate liver function, protein abundance, and histopathological status. Supplementing aloin at 20 mg kg^-1 was optimal for mitigating liver damage during NASH, as evidenced by reduced alanine transaminase and aspartate aminotransferase activity in serum. Supplementation with aloin significantly reduced serum concentration or liver protein abundance of malondialdehyde, tumor necrosis factor alpha, Interleukin (IL)-1β and IL-6. Aloin treatment enhanced hepatic superoxide dismutase activity, glutathione and serum IL-10 levels in mice with NASH. Furthermore, supplementation with aloin inhibited hepatocyte apoptosis caused by Bcl-2 up-regulation and cleaved caspase-3 and Bax down-regulation. Mechanistically, by using Nrf2 KO mice, the protective effects of aloin were associated with enhanced antioxidant, anti-inflammatory and anti-apoptotic activity, all of which were mediated by Nrf2/heme oxygenase-1 (HO-1) signaling activation. Data suggested that aloin activates the Nrf2/HO-1 pathway and has protective potential against liver injury during NASH. Therefore, aloin supplementation might contribute to the prevention and treatment of NASH via activation of the Nrf2/HO-1 pathway.

Anti-inflammatory and Anti-endoplasmic reticulum stress Effects of catalpol Against myocardial ischemia-reperfusion injury in streptozotocin-induced diabetic rats

The current study was designed to investigate the effects and the mechanism of catalpol on myocardial ischemia-reperfusion (MI/R) injury in a diabetic rat model. Male Sprague-Dawley rats were divided into DM + sham, DM +I/R, and DM +I/R + C groups and diabetes was induced using single injections of streptozotocin (STZ; 70 mg/kg; i.p). After confirming the induction of diabetes, rats were administered physiological saline and catalpol (10 mg/kg; i.p.) daily for 28 days. Subsequently, rats were subjected to left anterior descending (LAD) coronary artery occlusion for 30 min followed by reperfusion for 2 h. Haemodynamic parameters were recorded throughout surgery, and following sacrifice, hearts were isolated for biochemical, histopathological, and molecular analyses. Catalpol treatment significantly ameliorated MI/R injury by improving cardiac function, normalizing myocardial enzyme activities and markers of oxidative stress, and by maintaining myocardial architecture. Furthermore, expression levels of the inflammatory cytokines TNF-α and IL-6 were decreased in biochemical and immunohistochemical studies. Additionally, the cardioprotective effects of catalpol were partly related to reductions in myocardial endoplasmic reticulum stress (ERS). In conclusion, catalpol exerts cardioprotective effects in diabetic rats by attenuating inflammation and inhibiting ERS.

Ginsenoside Rb2 alleviates myocardial ischemia/reperfusion injury in rats through SIRT1 activation

The cardioprotective effects of ginsenoside Rb2 on oxidative stress, which is induced by hydrogen peroxide and myocardial ischemia/reperfusion (MI/R) injury, have been studied. The mechanisms were associated with the inhibition of cardiomyocyte apoptosis, a high concentration of antioxidant defense enzymes, and scavenging oxidative stress products. Because of the association with oxidative reaction and cardioprotection, sirtuin-1 (SIRT1) was selected as a promising target for investigating whether MI/R injury can be alleviated by ginsenoside Rb2 pretreatment through SIRT1 activation. The rats were exposed to ginsenoside Rb2 with or without SIRT1 inhibitor EX527 before ligation of coronary artery. Ginsenoside Rb2 reduced myocardial superoxide generation; downregulated gp91^phox expression; and decreased the mRNA expression levels and activities of interleukin-1β, interleukin-6, and tumor necrosis factor-α. The results demonstrated that ginsenoside Rb2 significantly attenuated oxidative stress and inflammation induced by MI/R injury. In addition, ginsenoside Rb2 upregulated SIRT1 expression and downregulated Ac-p53 expression. However, EX527 blocked the protective effects, indicating that the pharmacological action of ginsenoside Rb2 involves SIRT1. Our results thus revealed that ginsenoside Rb2 alleviated MI/R injury in rats by inhibiting oxidative stress and inflammatory response through SIRT1 activation. PRACTICAL APPLICATION: Ginsenoside Rb2 has a protective effect on MI/R injury by activating SIRT1 expression, reducing myocardium inflammation, and alleviating oxidative stress. Thus, ginsenoside Rb2 is a promising novel agent for ameliorating MI/R injury in ischemic heart diseases and cardiac surgery.

Targeted pharmacotherapy for ischemia reperfusion injury in acute myocardial infarction

INTRODUCTION

Achieving reperfusion immediately after acute myocardial infarction improves outcomes; despite this, patients remain at a high risk for mortality and morbidity at least for the first year after the event. Ischemia-reperfusion injury (IRI) has a complex pathophysiology and plays an important role in myocardial tissue injury, repair, and remodeling.

AREAS COVERED

In this review, the authors discuss the various mechanisms and their pharmacological agents currently available for reducing myocardial ischemia-reperfusion injury (IRI). They review important original investigations and trials in various clinical databases for treatments targeting IRI.

EXPERT OPINION

Encouraging results observed in many preclinical studies failed to show similar success in attenuating myocardial IRI in large-scale clinical trials. Identification of critical risk factors for IRI and targeting them individually rather than one size fits all approach should be the major focus of future research. Various newer therapies like tocilizumab, anakinra, colchicine, revacept, and therapies targeting the reperfusion injury salvage kinase pathway, survivor activating factor enhancement, mitochondrial pathways, and angiopoietin-like peptide 4 hold promise for the future.

Pharmacological Update Properties of Aloe Vera and its Major Active Constituents

Aloe vera has been traditionally used to treat skin injuries (burns, cuts, insect bites, and eczemas) and digestive problems because its anti-inflammatory, antimicrobial, and wound healing properties. Research on this medicinal plant has been aimed at validating traditional uses and deepening the mechanism of action, identifying the compounds responsible for these activities. The most investigated active compounds are aloe-emodin, aloin, aloesin, emodin, and acemannan. Likewise, new actions have been investigated for Aloe vera and its active compounds. This review provides an overview of current pharmacological studies (in vitro, in vivo, and clinical trials), written in English during the last six years (2014–2019). In particular, new pharmacological data research has shown that most studies refer to anti-cancer action, skin and digestive protective activity, and antimicrobial properties. Most recent works are in vitro and in vivo. Clinical trials have been conducted just with Aloe vera, but not with isolated compounds; therefore, it would be interesting to study the clinical effect of relevant metabolites in different human conditions and pathologies. The promising results of these studies in basic research encourage a greater number of clinical trials to test the clinical application of Aloe vera and its main compounds, particularly on bone protection, cancer, and diabetes.

Clinical Prescription-Protein-Small Molecule-Disease Strategy (CPSD), A New Strategy for Chinese Medicine Development: A Case Study in Cardiovascular Diseases

Chinese medicine is a national treasure that has been passed down for thousands of years in China. According to the statistics of the World Health Organization, there are currently four billion people in the world who use Chinese medicine to treat diseases, accounting for 80% of the world's total population. However, the obscurity of its theory, its unmanageable quality, its complex compositions, and the unknown effective substances and mechanisms are great obstacles to the internationalization of Chinese medicine. Here, we propose a new strategy for the development of Chinese medicine: the clinical prescription (C)-protein (P)-small-molecule (S)-disease (D) strategy, namely the CPSD strategy. The strategy uses clinical prescriptions as the source of medicine and uses computer simulation technology to find small-molecule drugs targeting therapeutic proteins for treating specific diseases so as to deepen awareness of the value of Chinese medicine. At the same time, this article takes cardiovascular drug development as an example to introduce the application of CPSD, which will be instrumental in the further development, modernization, and internationalization of Chinese medicine.

LncRNA TUG1 protects against cardiomyocyte ischaemia reperfusion injury by inhibiting HMGB1

The aim of this study was to investigate whether lncRNA TUG1 could mediate the progression of ischemia-reperfusion injury following acute myocardial infraction. Mouse cardiomyocytes HL-1 cells were subjected to oxygen glucose deprivation followed by reperfusion (OGD/R) to induce myocardial I/R injury. The expression of TUG1 was detected by real-time PCR. Overexpression or down expression of TUG1 was performed in mouse HL-1 cardiomyocytes. The myocardial cell viability and apoptosis were respectively detected. In addition, the expression levels of inflammatory factors, apoptosis-related proteins and HMGB1 proteins were detected. Besides, an inhibitor of HMGB1 was used to treat cells to verify the relationship between TUG1 and HMGB1 protein. The expression of TUG1 was significantly up-regulated in OGD/R-induced myocardial HL-1 cells. The overexpression of TUG1-induced inflammation and apoptosis in OGD-R-induced myocardial HL-1 cells. Knock down of TUG1 protected OGD/R-induced myocardial I/R injury by inhibiting HMGB1 expression. Suppression of lncRNA TUG1 may prevent myocardial I/R injury following acute myocardial infarction via inhibiting HMGB1 expression.

Barbaloin Attenuates Mucosal Damage in Experimental Models of Rat Colitis by Regulating Inflammation and the AMPK Signaling Pathway

Background

Barbaloin is one of the main medicinal ingredients of aloe vera, which displays various anti-inflammatory and anti-apoptosis properties in several inflammatory and fibrotic diseases. Our study evaluated its efficacy against dextran sulfate sodium (DSS)-induced colitis in rats.

Material/Methods

Ulcerative colitis (UC) rat models were established in vivo, and after barbaloin treatment, body weight and inflammation index were measured. Additionally, the signaling mechanism by which barbaloin protects against UC was investigated using LPS-infected Caco-2 cells.

Results

Barbaloin could significantly reverse UC-induced weight loss and colon injury. Further, it could effectively increase the mRNA expression of IL-4 and IL-10 in colon tissues, while decreasing the expression of IFN-γ, IL-6, IL-1β, and TNF-α. Furthermore, it significantly enhanced UC-inhibited atresia band 1 (ZO-1), occludin, and E-cadherin, and was also found to activate the AMPK signaling pathway. Additionally, si-RAN-induced knockdown, and overexpression assay showed that barbaloin could inhibit the UC-enhanced MLCK signaling pathway by activating the AMPK signaling pathway.

Conclusions

Barbaloin can effectively inhibit inflammation and reverse epithelial barrier function to protect against UC, possibly via activation of the AMPK signaling pathway.

Aloin Preconditioning Attenuates Hepatic Ischemia/Reperfusion Injury via Inhibiting TLR4/MyD88/NF-κB Signal Pathway In Vivo and In Vitro

Background

Aloin exerts considerable protective effects in various disease models, and its effect on hepatic ischemia-reperfusion (HIR) injury remains unknown. This research is aimed at conducting an in-depth investigation of the antioxidant, anti-inflammatory, and antiapoptosis effects of aloin in HIR injury and explain the underlying molecular mechanisms.

Methods

In vivo, different concentrations of aloin were intraperitoneally injected 1 h before the establishment of the HIR model in male mice. The hepatic function, pathological status, oxidative stress, and inflammatory and apoptosis markers were measured. In vitro, aloin (AL, C₂₁H₂₂O₉) or lipopolysaccharide (LPS) was added to a culture of mouse primary hepatocytes before it underwent hypoxia/reoxygenation (H/R), and the apoptosis in the mouse primary hepatocytes was analyzed.

Results

We found that 20 mg/kg was the optimum concentration of aloin for mitigating I/R-induced liver tissue damage, characterized by decreased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Aloin pretreatment substantially suppressed the generation of hepatic malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and IL-6 and enhanced the hepatic superoxide dismutase (SOD) activities as well as glutathione (GSH) and IL-10 levels in the liver tissue of I/R mice; this indicated that aloin ameliorated I/R-induced liver damage by reducing the oxidative stress and inflammatory response. Moreover, aloin inhibited hepatocyte apoptosis and inflammatory response that was caused by the upregulated expression of Bcl-2, the downregulated expression of cleaved caspase3(C-caspase3), Bax, Toll-like receptor 4 (TLR4), FADD, MyD88, TRAF6, phosphorylated IKKα/β (p-IKKα/β), and phosphorylated nuclear factor κB p65 (p-NF-κB p65).

Functional improvement and maturation of human cardiomyocytes derived from human pluripotent stem cells by barbaloin preconditioning

The development of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is a significant advancement in our ability to obtain cardiomyocytes in vitro for regenerative therapies and drug discovery. However, hPSC-CMs obtained via existing protocols usually exhibit a markedly immature phenotype, compared with adult cardiomyocytes, thereby limiting their application. Here we report that barbaloin preconditioning dramatically improves the morphology, structure-related cardiac gene expression, calcium handling, and electrophysiological properties of hPSC-CMs, which means that barbaloin may have the potential to induce the maturation of hPSC-CMs, providing a novel strategy to generate more adult-like cardiomyocytes and promoting the application of hPSC-CMs in regenerative medicine, drug development, and disease modeling.

Protective effect of Barbaloin in a rat model of myocardial ischemia reperfusion injury through the regulation of the CNPY2‑PERK pathway

Barbaloin (Bar) has a myocardial protective effect, but its mechanism of action is uncertain. The endoplasmic reticulum stress (ERS)-mediated apoptosis pathway serves an important role in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). Inhibiting ERS may significantly improve the progression of MIRI and serve a role in its prevention. Therefore, based on current knowledge of ERS-mediated cardiomyocyte apoptosis and the cardioprotective effect of Bar, the purpose of the present study was to further evaluate the myocardial protective effect and potential mechanisms of Bar pretreatment in MIRI. The present study established a MIR rat model and randomly divided these rats into four groups. Prior to myocardial ischemia, Bar (20 mg/kg) was administered to rats once daily for 1 week. Myocardial blood serum lactate dehydrogenase and creatine kinase were subsequently measured. A terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay was used to evaluate the myocardial protective effect of Bar pretreatment on MIRI. To assess whether the ERS signaling pathway was involved in the myocardial protection mechanism of Bar pretreatment, the expression levels of ERS-associated proteins, protein canopy homolog 2 (CNPY2), glucose regulatory protein 78, transcriptional activator 4, C/EBP-homologous protein (CHOP), PKR endoplasmic reticulum kinase (PERK), caspase-12 and caspase-3 were detected by western blot analysis, immunohistochemistry or reverse transcription-quantitative polymerase chain reaction. The results confirmed that Bar pretreatment significantly reduced the damage and the level of apoptosis caused by MIR. Bar pretreatment significantly inhibited the expression of ERS-associated proteins in cardiomyocytes. In addition, the immunohistochemistry results demonstrated that Bar pretreatment significantly inhibited the CNPY2-positive cell apoptosis ratio of cardiomyocytes. Therefore, the results of the current study suggested that CNPY2 is present in cardiomyocytes and participates in the development of MIRI by initiating the PERK-CHOP signaling pathway. Bar pretreatment may attenuate MIRI by inhibiting the CNPY2-PERK apoptotic pathway.

The Role of Traditional Chinese Medicine in the Regulation of Oxidative Stress in Treating Coronary Heart Disease

Oxidative stress has been closely related with coronary artery disease. In coronary heart disease (CHD), an excess of reactive oxygen species (ROS) production generates endothelial cell and smooth muscle functional disorders, leading to a disequilibrium between the antioxidant capacity and prooxidants. ROS also leads to inflammatory signal activation and mitochondria-mediated apoptosis, which can promote and increase the occurrence and development of CHD. There are several kinds of antioxidative and small molecular systems of antioxidants, such as β-carotene, ascorbic acid, α-tocopherol, and reduced glutathione (GSH). Studies have shown that antioxidant treatment was effective and decreased the risk of CHD, but the effect of the treatment varies greatly. Traditional Chinese medicine (TCM) has been utilized for thousands of years in China and is becoming increasingly popular all over the world, especially for the treatments of cardiovascular diseases. This review will concentrate on the evidence of the action mechanism of TCM in preventing CHD by modulating oxidative stress-related signaling pathways.

microRNA-135a protects against myocardial ischemia-reperfusion injury in rats by targeting protein tyrosine phosphatase 1B

microRNAs are an emerging class of molecules that regulate pathogenesis of cardiovascular diseases. Here we aim to elucidate the effects and mechanism of miR-135a, a previously reported regulator of ischemia-reperfusion (I/R) injury, in myocardial I/R injury. Quantitative real-time polymerase chain reaction analysis revealed that the expression level of miR-135a was significantly decreased both in the rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation. Overexpression of miR-135a in vivo markedly decreased the infarct size and inhibited the I/R-induced cardiomyocyte apoptosis. Overexpression of miR-135a in H9c2 also exerted antiapoptosis effects. Furthermore, bioinformatics analysis, luciferase activity, and the Western blot assay indicated that protein tyrosine phosphatase 1B (PTP1B) is a direct target of miR-135a. In addition, the expression of proapoptotic-related genes, such as p53, Bax, and cleaved caspase3, were decreased in association with the downregulation of PTP1B. In summary, this study demonstrates that miR-135a exerts protective effects against myocardial I/R injury by targeting PTP1B.

AMP-activated protein kinase sparks the fire of cardioprotection against myocardial ischemia and cardiac ageing

AMP-activated protein kinase (AMPK) is a pivotal regulator of some endogenous defensive molecules in various pathological processes, particularly myocardial ischemia (MI), a high risk of myocardial infarction. Thereby it is of great significance to explore the inherent mechanism between AMPK and myocardial infarction. In this review, we first introduce the structure and role of AMPK in the heart. Next, we introduce the mechanisms of AMPK in the heart; followed by the energy regulation of AMPK in MI. Lastly, the attention will be expanded to some potential directions and further perspectives. The information compiled here will be helpful for further research and drug design in the future before AMPK might be considered as a therapeutic target of MI.

The cardioprotective effects of secretory leukocyte protease inhibitor against myocardial ischemia/reperfusion injury

Protease enzymes generated from injured cells and leukocytes are the primary cause of myocardial cell damage following ischemia/reperfusion (I/R). The inhibition of protease enzyme activity via the administration of particular drugs may reduce injury and potentially save patients' lives. The aim of the current study was to investigate the cardioprotective effects of treatment with recombinant human secretory leukocyte protease inhibitor (rhSLPI) on in vitro and ex vivo models of myocardial I/R injury. rhSLPI was applied to isolated adult rat ventricular myocytes (ARVMs) subjected to simulated I/R and to ex vivo murine hearts prior to I/R injury. Cellular injury, cell viability, reactive oxygen species (ROS) levels, and levels of associated proteins were assessed. The results demonstrated that administration of rhSLPI prior to or during sI/R significantly reduced the death and injury of ARVMs and significantly reduced intracellular ROS levels in ARVMs during H₂O₂ stimulation. In addition, treatment of ARVMs with rhSLPI significantly attenuated p38 mitogen-activated protein kinase (MAPK) activation and increased the activation of Akt. Furthermore, pretreatment of ex vivo murine hearts with rhSLPI prior to I/R significantly decreased infarct size, attenuated p38 MAPK activation and increased Akt phosphorylation. The results of the current study demonstrated that treatment with rhSLPI induced a cardioprotective effect and reduced ARVM injury and death, intracellular ROS levels and infarct size. rhSLPI also attenuated p38 MAPK phosphorylation and activated Akt phosphorylation. These results suggest that rhSLPI may be developed as a novel therapeutic strategy of treating ischemic heart disease.

Barbaloin loaded polydopamine-polylactide-TPGS (PLA-TPGS) nanoparticles against gastric cancer as a targeted drug delivery system: Studies in vitro and in vivo

Gastric cancer is the third leading cause of cancer-associated death worldwide. Although a decrease in its incidence is observed, gastric cancer still poses a major clinical challenge due to poor prognosis and limited treatments. Barbaloin (BBL) is a main medicinal composition of the Chinese traditional medicine aloe vera. BBL has various bioactivities, including anti-oxidant, anti-inflammatory and anti-tumor properties. Polydopamine (pD)-based surface modification is easy to functionalize polymeric nanoparticles (NPs) surfaces with ligands and/or additional polymeric layers. In the present study, BBL-loaded formulations was developed with pD-modified NPs, which was synthesized by polylactide-TPGS (PLA-TPGS) (pD-PLA-TPGS/NPs). And galactosamine (Gal) was conjugated on the prepared NPs (Gal-pD-PLA-TPGS/NPs) for targeting the gastric cancer cells. Here, we found that BBL-loaded Gal-pD-PLA-TPGS/NPs showed the highest cellular uptake efficacy in gastric cancer cells. Gal-pD-PLA-TPGS/NPs more significantly reduced the gastric cancer cell viability. Further, greater apoptosis, autophagy and ROS generation was induced by Gal-pD-PLA-TPGS/NPs in gastric cancer cells. Additionally, compared to the other two NPs, Gal-pD-PLA-TPGS/NPs most markedly decreased ATP levels in gastric cancer cells. In vivo, Gal-pD-PLA-TPGS/NPs were specifically targeted to tumor site. Moreover, Gal-pD-PLA-TPGS/NPs exhibited the most anti-tumor effects, as evidenced by the lowest tumor volume and tumor weight. Of note, there was no significant difference was observed in body and liver weight, as well as the histological changes in major organs isolated from each group of mice. Together, the findings indicated that BBL-loaded Gal-pD-PLA-TPGS/NPs could be targeted to gastric cancer cells to suppress tumor progression without toxicity.